<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
		body,ul,li{
			margin:0;
			padding: 0;
		}
		ul,li{
			list-style: none;
		}
		.nav{
			width: 800px;
			height: 40px;
			background: pink;
			margin: 20px auto;
		}
		.nav ul li{
			float: left;

		}
		.nav ul li a{
			display: inline-block;
			height: 40px;
			font: 14px/40px 微软雅黑;
			padding:0 20px;
			text-decoration: none;
		}
		.nav ul li a:hover{
			background: #aaa;
		}

	</style>
</head>
<body>
	<div class="nav">
		<ul>
			<li><a href="#">百度</a></li>
			<li><a href="#">百度一下</a></li>
			<li><a href="#">14期威武</a></li>
		</ul>
	</div>
</body>
</html>